Egg consumption and its effect on type 2 diabetes

If you are a little fed up with receiving news in one direction (eggs are very bad, or eggs are very good) and then immediately receiving the opposite, I won't blame you, you have every right to do so. So much so that I think that the benefit/harm of egg consumption is one of the topics that has changed direction the most in such a short time and that generates the most debate.

So, and before we delve into what the most recent evidence supports and the studies that lead to it, it would not be amiss to draw a first conclusion: if the matter is so murky, the last thing we should do is draw totalizing, immobile and forceful conclusions.

The latest controversy

A recent article has once again sparked controversy regarding the health benefits/damages of eating eggs. This is Associations of Dietary Cholesterol or Egg Consumption With Incident Cardiovascular Disease and Mortality. It concludes that “Among US adults, higher dietary cholesterol or egg consumption was significantly associated with increased risk of CVD and all-cause mortality in a dose-response manner.” These are strong statements, even dangerous if they are not put into context, as they can easily be misinterpreted.

Fortunately Julio Basulto recently analyzed his circumstances in his article, in summary:

• This is an observational study, and as the authors themselves state in the article, these results do not allow a causal relationship to be established.
• Egg consumption in the study population was assessed in two unique questionnaires applied at the beginning and at the end of the study period, which was 30 years, and this information was also obtained by self-recording. In other words, the errors that can be incurred by following this methodology can be significant and, what is more, even probable.
• In that same assessment of egg consumption, no distinction was made between eggs that were consumed as such (i.e. fried eggs, omelettes, hard-boiled eggs, etc.) and those that were included in recipes that contained eggs. In other words, eggs present in recipes such as cakes, biscuits, pastries, flans, etc. were also counted. The reasonable doubt is, as Julio Basulto points out in his post, what if other ingredients present in these recipes, such as sugar, for example, facilitate this association? It certainly wouldn't be far-fetched.
• The authors make another point by stating that these results are relative to the North American population and that they may not be reproducible in other groups due to a different food environment, as well as a different epidemiological incidence of chronic diseases.

The history of the egg controversy and health prognosis

The affair comes from afar. More specifically, when in the 1970s the theory of cholesterol as the main risk factor for cardiovascular diseases began to become all the rage. It can be summed up in that today and with science in hand, the role of dietary cholesterol in cholesterolemia (amount of cholesterol in the blood) and that this in turn plays a role in cardiovascular risk is quite questionable.

That is to say, there are many and more important elements in the dietary field that predict a bad cardiovascular prognosis. That is what science is about, that today we know more than yesterday, although some groups or people, especially those who are stuck in their ways, sadly, find it difficult to adapt this new knowledge to clinical practice.

However, it is true that there are still mixed results among the most recent scientific articles published when it comes to assessing the role of eggs in health prognosis, and more specifically in relation to type 2 diabetes. Let's take a look at them.

Egg in the prognosis (and treatment) of type 2 diabetes

Most recent studies are not particularly alarming about the relationship between egg consumption and the risk of vascular disease, either among the general population or in patients with diabetes. In fact, I have not been able to find any study that, along the lines of the above, is so alarmist. Quite the contrary.

However, the debate is still alive and studies on these issues are repeated. The confirmation of this reality may only be a sign of our fears when it comes to closing down previous paradigms, now outdated, but which, as a remnant of the anti-cholesterol movement of yesteryear, continue to be a cause for concern.

Apparently, the egg continues to generate debate despite the many studies that, one by one, free it from that condemnation issued in the 1970s.

To name a few, this study, again observational and from 2015, concluded with little doubt that “a higher intake of eggs was associated with a lower risk of type 2 diabetes in a cohort of more than 2,300 middle-aged and older men.”

For its part, this intervention carried out for three months in 140 patients found that “a high consumption of eggs did not reflect changes in the lipid profile of people with type 2 diabetes who followed a diet rich in monounsaturated and polyunsaturated fatty acids.” Note that this high consumption of eggs was specified in this study in nothing more and nothing less than two eggs a day for 6 days a week.

And we could go on like this for a while. But among all those articles I would like to highlight this article from 2018: “ Egg consumption, cardiovascular diseases and type 2 diabetes ”. And I want to highlight it because in addition to talking about the subject in question, it highlights what we have talked about so many times in this corner about nutrition and type 2 diabetes: the importance of habits. Thus, its conclusions could not be clearer:

“ Dietary patterns, physical activity and genetics affect predisposition to cardiovascular disease and type 2 diabetes more than consideration of a single food such as eggs.

In short, up to seven eggs per week can be safely consumed, also in patients diagnosed with cardiovascular disease with type 2 diabetes, but always placing special emphasis on healthy lifestyles.”

There are even studies that, far from viewing the egg under the shadow of suspicion, consider it to be a beneficial element. According to the very recent study “ Mechanism and Potential of Egg Consumption and Egg Bioactive Components on Type-2 Diabetes” the relationship between egg consumption and the risk of type 2 diabetes based on observational epidemiological studies is not consistent. However, clinical intervention studies provide encouraging evidence that egg consumption improves the risk of this pathology.

That is, current research also indicates that some components of the egg, including some of its peptides, could be beneficial in the context of type 2 diabetes, both in relation to the amount of insulin secreted and in the sensitivity to this hormone, oxidative stress and inflammation. All of this suggests a possible application in the management of type 2 diabetes.

In short, and as far as I'm concerned, in addition to cardiovascular risk and type 2 diabetes… there are much more important things to focus on than the damn egg.

 

Post author: Juan Revenga, dietician-nutritionist ( @Juan_Revenga )